1. Field of the Invention
In general, the present invention relates to stringed musical instruments. More particularly, the present invention relates to the neck structure of stringed musical instruments.
2. Prior Art Description
Many stringed musical instruments, such as guitars, bass guitars, violins, cellos, and the like, have a neck structure that extends under the strings. Each string on such instruments is of different diameter, weight, and tension. In this manner, each of the strings on the instrument produces different musical tones when vibrated.
The strings of such instruments extend above the neck of the instrument. The tension produced by the strings is experienced along the neck of the instrument. Consequently, the neck must be strong enough to support the cumulative string tension created by the strings. The neck must also be rigid enough remain straight under the tension so that a constant string relief can be maintained in between the strings and the neck. Furthermore, the neck must not twist due to the asymmetric loading imposed by the various string tensions. Twisting would create an unplayable condition where one or more strings would touch the frets of the neck.
The traditional material for the neck of a stringed instrument is wood. Wood is used for its warm, tonal properties. However, wood has many disadvantages. Wood, being a natural material, can vary considerably within the same species. Wood may differ in strength, rigidity and tonal quality from piece-to-piece. Furthermore, wood is influenced by changes in temperature and humidity which causes the wood to expand and contract. In an instrument, the resulting dimensional changes affect the tone of the instrument.
In order to eliminate the many variables inherent in wooden necks, some instrument manufacturers have made necks with secondary materials that stabilize the wood. There are numerous examples in the prior art of composite materials being used to improve the performance of an instrument's neck. A popular design has been to use an internal wood core and provide fiber reinforcement around the exterior to retain the tonal properties of wood. Such prior art neck structures are exemplified by U.S. Pat. No. 4,950,437 to Lieber, entitled Molding Process For Musical Instrument Neck, and U.S. Pat. No. 4,951,542 to Chen, entitled Electric Guitar Neck.
In the prior art, wooden neck structures have also been reinforced with composite inserts that internally stabilize the wood. Such prior art is exemplified by U.S. Pat. No. 6,965,065 to McPherson, entitled, Neck For Stringed Musical Instrument and U.S. Pat. No. 6,888,055 to Smith and Blanda, entitled, Guitar Neck And Support Rod.
In the prior art record, instrument necks have been used that are totally synthetic and contain no wood at all. For instance, in U.S. Pat. No. 4,145,948 to Turner, entitled, Graphite Composite Neck For Stringed Musical Instruments, an instrument neck is shown that is made completely from a graphite (carbon) fiber reinforced plastic material. In U.S. Pat. No. 4,846,039 to Mosher, entitled, Neck For Stringed Musical Instruments, an instrument neck is described that is comprised of alternating layers of epoxy resin and powdered carbon. Finally, U.S. Pat. No. 6,100,458 to Carrington, entitled, Neck For Stringed Instrument, a neck structure is shown that is comprised of an internal foam core with exterior reinforcing fibers.
A problem associated with some synthetic instrument neck structures is that the synthetic necks tend to be solid and heavy. As a result, any instrument utilizing such a neck may have a different feel or balance as compared to the same instrument with a traditional wooden neck. This change in balance and increased weight is undesirable to many musicians.
In U.S. Pat. No. 5,895,872 to Chase, entitled Composite Structure For A Stringed Instrument, a lightweight synthetic neck assembly is shown. In this patent, a core material, such as dense foam, is wrapped with fiber reinforced resin, thereby forming the neck. The foam used to form such necks must be rather dense so that the foam core can withstand the wrapping and forming process without compressing out of its original shape.
The use of such dense foam neck structures does have disadvantages. In the Chase patent, the neck lacks the structure to be connected, such as with screws to the body of a guitar. Accordingly, in the Chase patent, the body of the guitar and the neck of the guitar had to be manufactured together as a single integral assembly in order to produce the stable interconnection needed between these components. Such a construction is clearly illustrated in FIG. 2 of the Chase patent. The result is that the neck of the Chase patent cannot be readily attached to conventional guitar bodies without requiring alterations to those guitar bodies.
Another disadvantage of dense foam filled neck structures, such as is shown in the Chase patent, is one of acoustics. When composite material is formed around a dense foam core, the dense foam core must be substantial enough to resist the external pressure of consolidation. As a result, the dense foam core must be heavy and dense in order to maintain significant structural strength. In addition, the dense foam core becomes trapped within the structure. The dense foam core absorbs sound energy. Consequently, the presence of the dense foam core limits the amount of resonance acoustics that can be achieved within the neck structure. Thus, an instrument neck having a foam core will have limited acoustical characteristics. In certain instruments, this absorption of sound may be desirable to prevent rattles and other extraneous sounds. However, in other instruments, the foam core may make the instrument sound “flat” due to the lack of harmonics in the neck.
With a compression molded foam core design, such as is found in the Chase patent, the removal of the foam core to create beneficial harmonics is not an option, because the foam core is an integral part of the neck structure.
A need therefore exists for an instrument neck structure that is synthetic and lightweight, yet has good acoustics, does not require a dense foam core, and can be added to existing instruments. This need is met by the present invention as described and claimed below.